Relationship between systemic hypertension, perfusion pressure and glaucoma: A comparative study in an adult Indian population

AIMS: To study the relationship between blood pressure (BP), intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and primary open angle glaucoma (POAG) in patients with hypertension and compare it to a control group of normotensives. DESIGN: Cross-sectional observational study. MATERIALS AND METHODS: A total of 108 subjects with primary hypertension and 100 age-matched controls without hypertension were enrolled for the study. IOP measurement using Noncontact Tonometer and dilated fundus evaluation using + 90 D lens were done for all cases. Single recording of BP was taken. Gonioscopy, Humphrey's central visual fields, optical coherence tomography and pachymetry were done for all subjects with IOP > 21 mm Hg or C: D ratio ≥ 0.5 or asymmetry of > 0.2. STATISTICAL ANALYSIS: Univariate and multivariate multinomial regression models were used to determine the association between covariates and risk of glaucoma or glaucoma suspect. RESULTS: There was no difference in the glaucoma status between subjects with and without hypertension. Subjects on antihypertensive medications were 1½ times more likely to have suspicious glaucoma (odds ratio [OR] =1.56] and nearly twice as likely to have POAG (OR = 1.85). In addition, we found a 31% and 12% reduction in risk of having POAG (95% confidence interval [CI] =13–45%, P = 0.001) and glaucoma suspect (95% CI = 2–21%, P = 0.03) respectively with every 1 mm Hg increment in MOPP. CONCLUSION: Subjects on antihypertensive medications are more likely to have either glaucoma or glaucoma suspect, and higher ocular perfusion pressure offers relative protection from glaucomatous damage.